#include<stdio.h>
int main()
{
    void fuckation(int,int),bigdick(int,int);
    char ch;
    int a=15,b=12;
    ch=getchar();
    switch (ch)
    {
    case 'a':
    case 'A':fuckation(a,b);
        break;
        case 'b':
        case'B':bigdick(a,b);
        break;
    
    default:putchar('\a');
        break;
    }
    return 0;
}
void fuckation(int x,int y)
{
    printf("x+y= %d \n",x+y);
}
void bigdick(int x,int y)
{
    printf("x-y=%d \n",x-y);
}